Return to Grace

Right near the start of the game, you'll climb up a wall and be faced with two bridges. They both lead to the same ace, so for the sake of simplicity take the right hand bridge. Shortly after crossing it there'll be what looks like a broken piece of wall to examine - coming frim this direction, it's almost impossible to miss!

Examine it when the prompt appears to unlock this simple achievement.

At the start of the game, when following the ping's direction from the device on your arm you will come across your first weather station, examine this and continue on to climb then there are two bridges (they lead the same place), choose the choose right side bridge for the opportunity to examine a land marker for this achievement.

Then continue on for the second weather station on your path for another achievement.

Timestamp:
00:02:25 - [01/02] Weather Station
00:03:15 - "Please send me a sign" Achievement
00:04:35 - [02/02] Weather Station
00:04:45 - "Elementary, my dear Watson" Achievement

This is 100% complete guide to achieve all trophies in game.
[All Timestamps are in comment on YouTube.]